How do we save our power grid from rising sea-levels?

Jacked Up

"No community should have to go through a devastating storm to learn that they are vulnerable."

Doug Marcy, coastal hazards specialist at the NOAA Coastal Services Center, uses a simple anecdote to explain most people's response to sea-level rise and coastal flooding. He says that if you place a frog in a pot of boiling water, it will immediately jump out. But if you drop the frog in cool water and then gradually raise the temperature, the frog won't notice until it's too late. That's life in the Lowcountry.

It's becoming more and more difficult to beat back the tides in Charleston. Not a month goes by now without city streets being washed out and closed off until the water recedes. Whether you call it nuisance flooding or a major threat may depend on whether you've had to abandon your car after stalling out in knee-high water. Either way, Charleston's flood problems are just getting started.

"Right now in Charleston, you get somewhere around 20 or 24 tidal flooding events per year, and that is really just when the tides get so high because you've got high tide on top of sea-level rise, they cause flooding, even on sunny days. Then when it rains, it just makes it much worse," says Nicole Hernandez Hammer, Southeast climate advocate with the Union of Concerned Scientists. "With the mid-range sea-level rise projections, you'll probably get around 78 of those events by the year 2030, and you're going to be looking at 187 of those events per year by the year 2045. As problematic as it seems now, this is the beginning of living with sea-level rise impact."

Duke Energy photo

In the past, Hammer has investigated the effects of sea-level rise on Florida's roadways. She has now begun to turn her focus to other areas along the East Coast to better understand how flooding threatens infrastructure and to compare how these communities are dealing with the problem.

"What we're doing here in Florida is we're putting in pumps and we're putting in barriers and sandbags, not very sophisticated stuff, and that's in the high-end places. The areas with very few resources, they're getting nothing," Hammer says. "The city of Miami Beach, which is just 18 square miles, a very tiny piece of Florida and Miami-Dade County, is spending half a billion dollars to deal with sunny-day flooding, and that really just amounts to pumps, raising roads, and those are the two kinds of things that are being done. You can imagine the costs associated with adapting an area if those are the figures you're looking at for a small stretch of Miami."

According to Hammer, it's important for any city faced with sea-level rise to devise a comprehensive plan that not only mitigates the harmful, everyday effects of flooding, but also looks at long-term solutions to adapting its infrastructure. But before city leaders can know how to plan for rising tides, they must understand what's at risk. Any Charleston commuter during a king tide can tell you what streets are prone to flooding, but what about the other components that make the city run? What about power?

Lights Out

A recent study conducted by members of the Union of Concerned Scientists examined the threat that sea-level rise and storm surges pose to the Lowcountry's electrical grid.

The study titled Lights Out: Storm Surge, Blackouts, and How Clean Energy Can Help projected flood mapping of five major metropolitan areas, including Charleston, and suggests that if "critical components of the electric grid are insufficiently protected, they risk inundation and flood damage and failure that can ensue." The study's analysis of the Lowcountry found that 54 major substations and seven power plants could be exposed to flooding from a major storm. Co-author of the study and energy research associate Julie McNamara says that the study is intended to present a catastrophic scenario for communities so that they take an intentional look at a city's vulnerabilities and build from there.

"We don't explicitly consider each substation and say whether or not it has been elevated, and we're not looking at exactly which power lines are going into each substation to know with certainty the level of redundancy in any sub-section of the grid," says McNamara. "That was intentional because we were hoping for this to be something of an indicator of the risk in order to trigger conversations at the local level. What is our utility doing? What are our regulators asking them to do or even allowing them to do? It's definitely a two-way street. It's not just on the utility."

Illustration by Scott Suchy

The report from the Union of Concerned Scientists looked at 18 power plants and 196 substations during their assessment of the area's flood impact. Researchers estimate that South Carolina can expect the sea to rise more than a foot by the year 2050. According to the study, "If storm surge from a Category 3 hurricane rolls in atop these higher seas, the impacts on coastal South Carolina could be severe. By 2050, seven power plants ... could be exposed to flooding. Four risk being exposed at a depth of five to 10 feet, and one at a depth of 10 to 15 feet."

The study also states that a majority of the 59 potentially exposed substations are located in areas expecting more than five feet of floodwater by 2050. Of these at-risk sites, 14 face projected flood levels of more than 10 to 15 feet.

When asked about how they prepare for flooding, SCE&G stated, "We have learned a lot from past storms. Since Hurricane Hugo hit Charleston in 1989, we have positioned new substation sites 14 feet above mean sea level. We constantly monitor and maintain our infrastructure to keep it in safe and optimum working condition."

The company also says that during the recent "1,000-year flood" in South Carolina, their peak number of outages was only around 15,000.

They added, "Those weren't substation-related, but instead were primarily due to fallen trees or limbs because of winds and saturated ground. To put that figure in context, we had more than 150,000 customers out at peak during the ice storm last year."

McNamara says that SCE&G has done a good job in preparing for current conditions, but she questions what that really means when considering future conditions.

"In South Carolina, it's been very difficult to have an open conversation in this area. What I've seen SCE&G saying about this is how they are looking at today's risks, but I think one of the most compelling findings of our research is how that risk is growing over time," she says. "If nothing else, it's economically inefficient to build for today for a piece of infrastructure that will be around facing an evolving threat over time. It's that part of the conversation that I have not heard them directly addressing."

S.C. Energy

To decide where South Carolina's energy infrastructure is headed, you have to understand where it is now. The Palmetto State is mostly powered by the atom. Ranking third in the nation for nuclear-generating capacity, about 54 percent of the state's net electricity came from four of South Carolina's nuclear power plants, according to the U.S. Energy Information Administration, and two new reactors are being added at the V.C. Summer Nuclear Station site in Fairfield County.

The state has little in the way of petroleum, coal, and natural gas, which are all imported. South Carolina's natural gas supply is piped in from the Gulf of Mexico and is mainly used by the electric power sector, while the state receives its supply of coal from Kentucky, Pennsylvania, Illinois, and Tennessee. The coal delivered to South Carolina is mainly used to generate electricity in power plants.

Courtesy of Nuclear Regulatory Commission

A massive portion of the V.C. Summer nuclear facility traveled from the Port of Charleston to the Midlands in 2014 on a specially-built train car

In 2013, renewable resources accounted for only five percent of the state's net electricity generated, with most of that coming from hydroelectric power. While South Carolina is still finding its way when it comes to renewable energy, the push to diversify both state and community resources will become more important as rising sea levels threaten the current infrastructure.

"You reduce the importance of any one asset on the grid the further you get away from a centralized system, and I think one of the great things about resilient, renewable resources beyond them being clean is that they can generate money for you even if the power hasn't gone out," says McNamara. "You can still be making money off of your solar panels when everything is fine. You can't say that for diesel generators. It's been widely reported that during Hurricane Sandy some 50 percent of diesel generators failed in New York City. When you aren't running them very often, you have a higher rate of failure just because of inactivity or failed maintenance."

In recent months, SCE&G has made strides in further developing the area's production of solar power by offering incentives and opening a solar energy farm in North Charleston. This focus on alternative energy sources will become even more important for South Carolina as the country's nuclear reactors reach the end of their lifespan. According to Bloomberg Business and the Nuclear Regulatory Commission, the permits for the state's four main reactors expire by 2050, much like the bulk of the nation's other nuclear reactors. The commission is considering extending these operating licenses, but the organization must fully investigate the long-term safety and security of continued reactor operation. When factoring in that these power plants have been licensed for 60 years, it becomes even more apparent that Charleston must start planning for tomorrow's infrastructure today.

Duke Energy photo

Oconee Nuclear Station sits on Lake Keowee in Oconee County

"On the one hand, the electric grid is at risk. Coastal flooding poses a serious threat today. You just look at the number of substations that could be exposed. We're not saying that any given storm would knock all those out at once, but it absolutely needs to be a part of the conversation," says McNamara. "Then, if you look at how sea-level rise can be changing that threat, increasing that threat over time, there's significant growth in the exposure potential, meaning that more infrastructure will be placed at risk. If you're building infrastructure that will last several decades without thinking of what could be changing in those next 40 years, you're ignoring a great risk."

According to McNamara and the other researchers who contributed to the report, while retreating from the encroaching coastline is an option, it's also important to consider a variety of energy sources when powering the city. A focus on cleaner energy will not only strengthen the resiliency of Charleston's infrastructure, it will also serve to reduce harmful emissions and lengthen the lifespan of the peninsula as a whole.

"We know that sea levels are going up and they are going up quickly because of climate change. What's happening in places like Florida, where we get most of our energy from non-renewable sources, is that we're putting in place all these types of structures and all this work that relies on dirty energy to be able to adapt," says Hammer. "By doing these things, we are contributing more to the problem in the long run, so I think it's important that we look at the big picture. What do we need to deal with the flooding? What's the root of all this and how do we come up with a comprehensive plan to address this? We're talking about adaptation and mitigation together."

McNamara and her fellow researchers hope that their work will spark a movement for the coastal communities they examined. Perhaps Charleston will begin a major effort to address sea-level rise before things get any worse and before it's too late.

"No community should have to go through a devastating storm to learn that they are vulnerable. If you can get the conversation going before they have to deal with those impacts, all the better," says McNamara. "The more you can draw risks to people's attention, the hope is the more action that will take place before a storm takes place. There's a lot that can be done and a lot that needs to be done. There's a lot of catching up to do."